Inlet control for reciprocating engines



Patented Nov. 17, 1925.

PATENT OFFICE.

KURT LIGNIEZ, OF MANNHEIM; GERMANY.

INLET CONTROL FOR RECIPROCATING ENGINES.

Application filed (ctcber 10, 1923. Serial No. 667,611.

To all" whom 'it may concern:

Be it known that I, KURT LIGNIEZ, a citizen of Germany, residing at Mannheim,

Badenia, Germany, have invented new and useful Improvements in Inlet Controls for Reciprocating Engines, of which the following is a specification.

This invention relates to an automatic inlet valve mechanism for reciprocating en- 0 gines in which a cut-oitl member positioned toynormally open an inlet is actuated by throttling the working Iiuid` to close the inlet. Y

The object of the present invention is a mechanism which will start, operate and stop theengine by means of the throttlevalve lever, moreover, to obtain small steam volumes with full inlet pressure, further, to govern the engine speed by` automatically cutting off the Steam supply.

Theipresent invention consists of the novel combination of an automatic inlet valve mechanism,` whoseAcut-oif member is actuated bv throttling of the workingvapor, with alr slide valve which accomplishes the function of inlet lead, cut-off, exhaust lead, and -compression in the usual manner, but which relieves the automatic inlet valve mechanism of pressure in an entirely new way, thus opening it.

In all heretofore known types of automatic inlet valve mechanisms opening of the inlet was accomplished either by exceedingly high compression, which necessarily used to equal the inlet steam. pressure, or by means of inlet-valves, which were opened by the piston just before dead center, 1n order to till the clearance space with live steam.

The automatic inlet-valve is relieved by uncovering a port leading to the steam-chest, and admitting a small volume of high-pressure steam. The area of this port may be so reduced that the inlet-steam has insuicient time to releave the inletsvalve mechanism, which then remains tightly shut, producing a number of extremely etective suspension strokes of the slide valve, because under these conditions no steam is admitted to the clearance space. The inlet-valve mechanism does not again open until the engine speed has decreased considerably.

The invention resides more particularly in the novel combinations hereinafter described and claimed, reference being made to the accompanying drawing' in which Fig. 1 represents a vertical section of a portion of a steam engine showing the preferred form of the invention.

Fig. 2 illustrates various diagrams.

Referring to Fig. 1 of the drawing, the steam enters the steam chest 5 by means of theinlet port 16 and passes under the end of the spring' plate 6 and into the inlet-port 7 which remains filled with steam as long as the spring plate is open. The slide-valve 8 permits the steam to pass through the port 9 into the cylinder 10 and it is exhausted `through an outlet port 17 from the steam chest.` The piston 11 moves with increasing velocity from headf end dead center toward its midstroke position, meanwhile the steam is subjected to constantly greater throttling until, let us say, at 15% cut-off, the excess inlet-steam pressure on the end of the `spri11g-plate closes the inlet-port 7. In the meantime the ports controlled by the slidevalve stay open up to 80% cut-ofi` volume without the additional admission of any live steam. i

As soon as the slidevalve has closed port 9 the relief port 13 connecting the cylinder with the steam chest is opened and suiiicient live steam enters, the end of the automatic inlet-valve is released and opens port 7. After the inlet port 7 has been closed the port 9 remains open for a brief space to allow the spaces 7 and 9 to take part in the expansion of the steam in the cylinder pro ducing reduced pressure. This reduced pressure allows the inlet-valve mechanism to remain closed until the relief port 13 has been opened. If the relief port is suiciently small.. the steam will not have time enough to release the spring-plate at the maximum rotational speed. The spring-plate remains closed temporarily and all steam is cut off until the speed drops.

In Fig. 2 a diagram 1 is shown denoting the start with full stroke cut-oif and greatly throttled inlet steam pressure, while diagram 2 shows the action with fully opened throttle valve, full inlet steam pressure and approximately 20% cut-0E. Diagram 3 shows the suspension of a charge due to the rapid ini-low of steam into the clearance space of the cylinder at the moment when the maximum permissible rotational speed has been attained.

By combining the automatic inlet-valve mechanism with a slide valve reversing is accomplished with a single movement of the reversing lever, starting takes place by moving the slide-valve lever, gradually at iirst, it being fully opened only after the engine has reached a certain rotational speed. The high pressure steam, acting together with a sutliciently high engine speed then automatically produces cut-oil' at the inlet-valve.

The highei` the rotational speed the earlier the cut-oli, consequently the machine, even With nonadj ustable spring-gab and with Widely varying engine loads soon reaches a state of rotational stability which lies Within limits permissibly 'close to the normal rotational speed.

A salient new feature is the suspension of steam admission to the cylinder at and beyond that point Where the engine exceeds its highest permissible rotational speed. This is effected by the combination of the automatic inlet-valve mechanism and the Vslide-valve. At the beginning of inlet lead the clearance space is only partly filled with steam thus the steam flows into the clearance space with a certain velocity during the period of inlet v'lead and may be so throttled in the spring clearance gab, according to the rotational speed of the engine, that even if the piston is on dead center the inlet-valve mechanism is closed, therefore when the engine exceeds a certain speed the steam-supply is completely cut olf. Strokes with smaller and larger partial cut-ofi1 volumes then alternate with strokes during which steam is completely cut off.

l claim l. An inlet control for reciprocating engines comprising a chest with a steam inlet, a chamber provided with a slide valve, an inlet port in the steam chest communicating with the chamber, a cut-oil' plate arranged in the steam chest to normally open the inlet port, and a relief port located in the Wall of the slide valve chamber leading from the steam chest into the chamber opened by the side valve When the inlet is closed so as to relieve the pressure on the plate to open the port.

2. An inlet control for reciprocating engines comprising a chest with a steam inlet, a chamber provided with a slide valve, an inlet port in the steam chest communicating With the chamber, a cut-off spring plate arranged in the steam chest to normally open the inlet port and close it by iexing the plate, and a relief port located in the Wall of the slide valve chamber leading from the steam chest into the chamber opened by the slide valve When the inlet is closed so as to relieve the pressure on the spring plate to open the port. Y

In testimony whereof I have hereunto set my hand.

KURT LIGNIEZ. 

